Vi/Vim Software

tvim is a gui wrapper around gvim's remote interface, it does two things 1). lets you open files in any already running copy of gvim (lets you select which). 2). opens the files in tabs TVim is released under the GPL version 3

Vim in C++. Not necessarily strictly vim or vi compatible or designed to be highly portable.
Project will make heavy use of STL and the Boost library. Probably no support for vimscript. Instead, python will be the scripting language of choice

Vimper is a Vim based IDE, a set of plugins to enable creation of development projects. There are a lot of useful plugins available, but you need to run around to gather them. Vimper gathers a lot of these plugins into one package and extend or add new.